single global observers root node (#25)

plus auto name observer macro `global_observer`

src/abilities/gun.rs

@@ -1,7 +1,7 @@
 use super::{Projectile, TriggerGun};
 use crate::{
-    GameState, billboards::Billboard, loading_assets::GameAssets, physics_layers::GameLayer,
-    sounds::PlaySound, utils::sprite_3d_animation::AnimationTimer,
+    GameState, billboards::Billboard, global_observer, loading_assets::GameAssets,
+    physics_layers::GameLayer, sounds::PlaySound, utils::sprite_3d_animation::AnimationTimer,
 };
 use avian3d::prelude::{
     Collider, CollisionLayers, CollisionStarted, LayerMask, PhysicsLayer, Sensor,
@@ -30,7 +30,8 @@ pub fn plugin(app: &mut App) {
         Update,
         (update, shot_collision, timeout).run_if(in_state(GameState::Playing)),
     );
-    app.add_observer(on_trigger_state);
+
+    global_observer!(app, on_trigger_gun);
 }
 
 fn setup(mut commands: Commands, assets: Res<GameAssets>, mut sprite_params: Sprite3dParams) {
@@ -43,7 +44,7 @@ fn setup(mut commands: Commands, assets: Res<GameAssets>, mut sprite_params: Spr
     });
 }
 
-fn on_trigger_state(
+fn on_trigger_gun(
     trigger: Trigger<TriggerGun>,
     mut commands: Commands,
     query_transform: Query<&Transform>,

src/abilities/mod.rs

@@ -4,6 +4,7 @@ mod thrown;
 use crate::{
     GameState,
     aim::AimTarget,
+    global_observer,
     heads::ActiveHeads,
     hitpoints::Hit,
     physics_layers::GameLayer,
@@ -74,7 +75,7 @@ pub fn plugin(app: &mut App) {
 
     app.add_systems(Update, enemy_hit.run_if(in_state(GameState::Playing)));
 
-    app.add_observer(on_trigger_state);
+    global_observer!(app, on_trigger_state);
 }
 
 fn enemy_hit(

src/abilities/thrown.rs

@@ -1,7 +1,12 @@
 use super::TriggerThrow;
 use crate::{
-    GameState, billboards::Billboard, hitpoints::Hit, loading_assets::GameAssets,
-    physics_layers::GameLayer, sounds::PlaySound, utils::sprite_3d_animation::AnimationTimer,
+    GameState,
+    billboards::Billboard,
+    hitpoints::Hit,
+    loading_assets::GameAssets,
+    physics_layers::GameLayer,
+    sounds::PlaySound,
+    utils::{global_observer, sprite_3d_animation::AnimationTimer},
 };
 use avian3d::prelude::*;
 use bevy::{pbr::NotShadowCaster, prelude::*};
@@ -35,8 +40,9 @@ pub fn plugin(app: &mut App) {
     app.add_systems(OnEnter(GameState::Playing), setup);
     app.add_systems(Update, shot_collision.run_if(in_state(GameState::Playing)));
     app.add_systems(FixedUpdate, update_auto_rotation);
-    app.add_observer(on_trigger_state);
-    app.add_observer(on_explosion);
+
+    global_observer!(app, on_trigger_thrown);
+    global_observer!(app, on_explosion);
 }
 
 fn on_explosion(
@@ -75,7 +81,7 @@ fn setup(mut commands: Commands, assets: Res<GameAssets>, mut sprite_params: Spr
     });
 }
 
-fn on_trigger_state(
+fn on_trigger_thrown(
     trigger: Trigger<TriggerThrow>,
     mut commands: Commands,
     query_transform: Query<&Transform>,

src/aim/marker.rs

@@ -1,4 +1,4 @@
-use crate::{GameState, loading_assets::UIAssets, utils::billboards::Billboard};
+use crate::{GameState, global_observer, loading_assets::UIAssets, utils::billboards::Billboard};
 use bevy::prelude::*;
 use bevy_sprite3d::{Sprite3dBuilder, Sprite3dParams};
 use ops::sin;
@@ -15,7 +15,7 @@ pub enum MarkerEvent {
 
 pub fn plugin(app: &mut App) {
     app.add_systems(Update, move_marker.run_if(in_state(GameState::Playing)));
-    app.add_observer(marker_event);
+    global_observer!(app, marker_event);
 }
 
 fn move_marker(mut query: Query<&mut Transform, With<TargetMarker>>, time: Res<Time>) {

src/backpack/backpack_ui.rs

@@ -1,5 +1,7 @@
 use super::{BackbackSwapEvent, Backpack, UiHeadState};
-use crate::{GameState, heads::HeadsImages, loading_assets::UIAssets, sounds::PlaySound};
+use crate::{
+    GameState, global_observer, heads::HeadsImages, loading_assets::UIAssets, sounds::PlaySound,
+};
 use bevy::prelude::*;
 
 static HEAD_SLOTS: usize = 5;
@@ -51,7 +53,7 @@ pub fn plugin(app: &mut App) {
             .run_if(in_state(GameState::Playing)),
     );
 
-    app.add_observer(swap_head_inputs);
+    global_observer!(app, swap_head_inputs);
 }
 
 fn setup(mut commands: Commands, assets: Res<UIAssets>) {

src/cash.rs

@@ -1,4 +1,4 @@
-use crate::{GameState, loading_assets::UIAssets, sounds::PlaySound};
+use crate::{GameState, global_observer, loading_assets::UIAssets, sounds::PlaySound};
 use bevy::prelude::*;
 
 #[derive(Component, Reflect, Default)]
@@ -25,10 +25,11 @@ pub fn plugin(app: &mut App) {
         Update,
         (rotate, update_ui).run_if(in_state(GameState::Playing)),
     );
-    app.add_observer(on_collect);
+
+    global_observer!(app, on_cash_collect);
 }
 
-fn on_collect(
+fn on_cash_collect(
     _trigger: Trigger<CashCollectEvent>,
     mut commands: Commands,
     mut cash: ResMut<CashResource>,

src/cash_heal.rs

@@ -1,11 +1,11 @@
 use crate::{
-    abilities::TriggerCashHeal, cash::CashResource, hitpoints::Hitpoints, player::Player,
-    sounds::PlaySound,
+    abilities::TriggerCashHeal, cash::CashResource, global_observer, hitpoints::Hitpoints,
+    player::Player, sounds::PlaySound,
 };
 use bevy::prelude::*;
 
 pub fn plugin(app: &mut App) {
-    app.add_observer(on_heal_trigger);
+    global_observer!(app, on_heal_trigger);
 }
 
 fn on_heal_trigger(

src/cutscene.rs

@@ -1,6 +1,7 @@
 use crate::{
     GameState,
     camera::{CameraState, MainCamera},
+    global_observer,
     tb_entities::{CameraTarget, CutsceneCamera, CutsceneCameraMovementEnd},
 };
 use bevy::prelude::*;
@@ -23,7 +24,8 @@ enum CutsceneState {
 pub fn plugin(app: &mut App) {
     app.init_resource::<CutsceneState>();
     app.add_systems(Update, update.run_if(in_state(GameState::Playing)));
-    app.add_observer(on_start_cutscene);
+
+    global_observer!(app, on_start_cutscene);
 }
 
 fn on_start_cutscene(

src/gates.rs

@@ -1,13 +1,14 @@
 use crate::{
-    cutscene::StartCutscene, keys::KeyCollected, movables::TriggerMovableEvent, sounds::PlaySound,
+    cutscene::StartCutscene, global_observer, keys::KeyCollected, movables::TriggerMovableEvent,
+    sounds::PlaySound,
 };
 use bevy::{prelude::*, utils::hashbrown::HashSet};
 
 pub fn plugin(app: &mut App) {
-    app.add_observer(on_key);
+    global_observer!(app, on_key_collected);
 }
 
-fn on_key(trigger: Trigger<KeyCollected>, mut commands: Commands) {
+fn on_key_collected(trigger: Trigger<KeyCollected>, mut commands: Commands) {
     match trigger.event().0.as_str() {
         "fence_gate" => {
             commands.trigger(StartCutscene("fence_01".to_string()));

src/heads/mod.rs

@@ -4,6 +4,7 @@ use crate::{
     GameState,
     abilities::HeadAbility,
     backpack::{BackbackSwapEvent, Backpack},
+    global_observer,
     hitpoints::Hitpoints,
     player::{Player, head_id_to_str},
     sounds::PlaySound,
@@ -133,8 +134,8 @@ pub fn plugin(app: &mut App) {
         (reload, sync_hp).run_if(in_state(GameState::Playing)),
     );
 
-    app.add_observer(on_select_active_head);
-    app.add_observer(on_swap_backpack);
+    global_observer!(app, on_select_active_head);
+    global_observer!(app, on_swap_backpack);
 }
 
 fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {

src/keys.rs

@@ -1,5 +1,5 @@
 use crate::{
-    GameState, billboards::Billboard, loading_assets::GameAssets, player::Player,
+    GameState, billboards::Billboard, global_observer, loading_assets::GameAssets, player::Player,
     sounds::PlaySound, squish_animation::SquishAnimation,
 };
 use avian3d::prelude::*;
@@ -18,10 +18,11 @@ pub struct KeyCollected(pub String);
 
 pub fn plugin(app: &mut App) {
     app.add_systems(Update, collect_key.run_if(in_state(GameState::Playing)));
-    app.add_observer(on_spawn);
+
+    global_observer!(app, on_spawn_key);
 }
 
-fn on_spawn(trigger: Trigger<KeySpawn>, mut commands: Commands, assets: Res<GameAssets>) {
+fn on_spawn_key(trigger: Trigger<KeySpawn>, mut commands: Commands, assets: Res<GameAssets>) {
     let KeySpawn(position, id) = trigger.event();
 
     let angle = rand::random::<f32>() * PI * 2.;

src/main.rs

@@ -145,6 +145,7 @@ fn main() {
     app.add_plugins(hitpoints::plugin);
     app.add_plugins(cash_heal::plugin);
     app.add_plugins(debug::plugin);
+    app.add_plugins(utils::observers::plugin);
 
     app.init_state::<GameState>();
 

src/movables.rs

@@ -1,5 +1,5 @@
 use crate::{
-    GameState,
+    GameState, global_observer,
     tb_entities::{Movable, MoveTarget},
 };
 use bevy::{prelude::*, utils::HashSet};
@@ -20,10 +20,11 @@ pub struct TriggerMovableEvent(pub HashSet<String>);
 pub fn plugin(app: &mut App) {
     app.register_type::<ActiveMovable>();
     app.add_systems(Update, move_active.run_if(in_state(GameState::Playing)));
-    app.add_observer(trigger);
+
+    global_observer!(app, on_movable_event);
 }
 
-fn trigger(
+fn on_movable_event(
     trigger: Trigger<TriggerMovableEvent>,
     mut commands: Commands,
     uninit_movables: Query<

src/player.rs

@@ -7,6 +7,7 @@ use crate::{
         Controls,
         controller::{CharacterControllerBundle, MovementBundle, PlayerMovement},
     },
+    global_observer,
     heads::HeadChanged,
     hitpoints::Hitpoints,
     loading_assets::GameAssets,
@@ -57,7 +58,7 @@ pub fn plugin(app: &mut App) {
         (rotate_view_keyboard, rotate_view_gamepad).run_if(in_state(GameState::Playing)),
     );
 
-    app.add_observer(update_head);
+    global_observer!(app, on_update_head);
 }
 
 fn spawn(
@@ -242,7 +243,7 @@ fn toggle_animation(
     }
 }
 
-fn update_head(
+fn on_update_head(
     trigger: Trigger<HeadChanged>,
     mut commands: Commands,
     asset_server: Res<AssetServer>,

src/sounds.rs

@@ -1,4 +1,4 @@
-use crate::loading_assets::AudioAssets;
+use crate::{global_observer, loading_assets::AudioAssets};
 use bevy::prelude::*;
 
 #[derive(Event, Clone, Debug)]
@@ -19,10 +19,10 @@ pub enum PlaySound {
 }
 
 pub fn plugin(app: &mut App) {
-    app.add_observer(spawn_sounds);
+    global_observer!(app, on_spawn_sounds);
 }
 
-fn spawn_sounds(
+fn on_spawn_sounds(
     trigger: Trigger<PlaySound>,
     mut commands: Commands,
     // sound_res: Res<AudioAssets>,

src/utils/mod.rs

@@ -1,3 +1,6 @@
 pub mod billboards;
+pub mod observers;
 pub mod sprite_3d_animation;
 pub mod squish_animation;
+
+pub(crate) use observers::global_observer;

src/utils/observers.rs

@@ -0,0 +1,35 @@
+use bevy::prelude::*;
+
+#[macro_export]
+macro_rules! global_observer {
+    ($app:expr,$system:expr) => {{
+        $app.world_mut()
+            .add_observer($system)
+            .insert(Name::new(stringify!($system)))
+    }};
+}
+
+pub use global_observer;
+
+pub fn plugin(app: &mut App) {
+    app.add_systems(Update, global_observers);
+}
+
+fn global_observers(
+    mut cmds: Commands,
+    query: Query<Entity, (With<Observer>, Without<Parent>, Added<Observer>)>,
+    mut root: Local<Option<Entity>>,
+) {
+    if root.is_none() {
+        let new_root = cmds.spawn(Name::new("Observers")).id();
+        *root = Some(new_root);
+    }
+
+    let Some(root) = *root else {
+        return;
+    };
+
+    for o in query.iter() {
+        cmds.entity(root).add_child(o);
+    }
+}